Direct-current plasma emission

Solutions and precipitates were analyzed on a Beckman Spectra-Span VI direct current plasma emission spectrophotometer (DCP), Precision for the Ca2 + analyses was 3% and for the Ba2 + 2% except for the most dilute samples In which It rose as high as 5%. Calcite mineralogy was determined on a Philips x-ray diffractometer calcite was the only phase recorded except In speed runs of under one hour In duration (not Included In this study) which produced vaterite. Details of analytic procedures are available In Pingitore and Eastman (30,31). 

For the routine determination of analytes in the quality control of the production of speciality chemicals, a combination of direct current plasma emission spectroscopy (DCP-OES) with flow injection analysis (FIA) has been used. Results obtained for the determination of boron, copper, molybdenum, tungsten and zinc in non-aqueous solutions have been published by Brennan and Svehla [3], The principle has been extended to other analytes, carrier liquids, and solvents, and the details of a fully automatic system have been described by Brennan et al. [4]. 

Determination of markers in digesta and feces by direct current plasma emission spectroscopy. Journal of Dairy Science 75, 2176-2183. 

Emission Spectrometry DCPAES = Direct Current Plasma Emission Spectrometry FAFS = Flame Atomic Fluorescence Spectrometry FAAS = Flame Atomic Absorption Spectrometry. 

In contrast to gas chromatographic separations, which require the preparation of volatile derivatives of tin compounds, separations carried out by means of HPLC do not necessarily require preparations of derivatives. HPLC has been used in conjunction with several detection techniques, including photometers, atomic absorption spectrometers and direct current plasma emission spectrometers after hydride generation. Some recent studies have involved fluorimetric detection (Kleibohmer and Cammann, 1989) and hydride generation AAS. The latter has been applied to the quantification of TBT in coastal water. 

Childress, W.L., Erickson, D. and Krull, I.S. (1992) Trace selenium speciation via high-performance liquid chromatography with ultraviolet and direct-current plasma emission detection. In Element-specific Chromatographic Detection by Atomic Emission Spectroscopy (ed. Uden, PC.). American Chemical Society, Washington, DC, pp. 257-273. 

High performance liquid chromatography coupled with hydride generation-direct current plasma emission spectrometry has been used for trace analysis and speciation studies of methylated organotin compounds in water [263],... 

Total tin was determined by continuous on-line hydride generation followed by direct current plasma emission spectroscopy. Interfacing the hydride generation-DC plasma emission spectrometric system with high performance liquid chromatography allowed the determination of tin species. Detection limits, sensitivities and calibration plots were determined. 

Krull IS, Panaro KW, Gershman LL. 1983. Trace analysis and speciation for Cr(VI) and Cr(ffl) via HPLC-direct current plasma emission spectroscopy (HPLC-DCP). J Chromatogr Sci 2L460M72. 

Urasa IT, Nam SH. 1989. Direct determination of chromium(III) and chromium(VI) with ion chromatography using direct current plasma emission as element-selective detector. J Chromatogr Sci 27 30-37. 

Belliveau JF, Griffiths WC, Wright CG and Tucci JR (1991) A direct current plasma emission spectrometric procedure for the assay of silicon in urine. Ann Clin Lab Sci 21 328-334. 

Roberts NB and Williams P (1990) Silicon measurement in serum and urine by direct current plasma emission spectrometry. Clin Chem 36 1460-1465. 

Krull, I.S. and Panaro, K.W. (1985). Trace Analysis and Speciation of Methylated Orga-notins by HPLC Hydride Generation Direct Current Plasma Emission Spectroscopy. Appl. Spectrosc., 39, 960. 

Lajunen. L.H.J., Kinnunen, A. and Yrjnheikki, E. (1985) Determination of mercury in biood and fish samples by cold-vapor atomic absorption and direct current plasma emission spectrometry. At. Spectrosc., 6,49-52. 

Bulk chemical analysis X-ray fluorescence spectroscopy Atomic absorption spectroscopy Inductively coupled plasma emission spectroscopy Direct-current plasma emission spectroscopy Arc emission spectroscopy Gravimetry Combustion Kjeldahl Impurities... 

In the 1980s and 1990s, some progress has been made in the use of analytical techniques for determining Mo in soils and crops. It has not been researched as extensively as other micronutrients because its deficiency is not as widespread as those of the other micronutrients. In addition to the colorimetric methods used in the past, it can now be successfully analyzed by graphite-furnace atomic-absorption spectrometry and direct-current plasma-emission spectrometry. 

The three universal extractants, ammonium carbonate, ammonium acetate, and AB-DTPA, have an advantage in that the extracts can be read directly for their Mo concentrations by graphite-furnace atomic-absorption spectrometry, direct-current plasma-emission spectrometry. 

A number of very useful and practical element selective detectors are covered, as these have already been interfaced with both HPLC and/or FIA for trace metal analysis and spe-ciation. Some approaches to metal speciation discussed here include HPLC-inductively coupled plasma emission, HPLC-direct current plasma emission, and HPLC-microwave induced plasma emission spectroscopy. Most of the remaining detection devices and approaches covered utilize light as part of the overall detection process. Usually, a distinct derivative of the starting analyte is generated, and that new derivative is then detected in a variety of ways. These include HPLC-photoionization detection, HPLC-photoelectro-chemical detection, HPLC-photoconductivity detection, and HPLC-photolysis-electrochemical detection. Mechanisms, instrumentation, details of interfacing with HPLC, detector operations, as well as specific applications for each HPLC-detector case are presented and discussed. Finally, some suggestions are provided for possible future developments and advances in detection methods and instrumentation for both HPLC and FIA. 

Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is used for multi-element determinations in blood and tissue samples. Detection in urine samples requires extraction of the metals with a polydithiocarbamate resin prior to digestion and analysis (NIOSH 1984a). Other satisfactory analytical methods include direct current plasma emission spectroscopy and determination by AAS, and inductively coupled argon plasma spectroscopy-mass spectrometry (ICP-MS) (Patterson et al. 1992 Shaw et al. 1982). Flow injection analysis (FIA) has been used to determine very low levels of zinc in muscle tissue. This method provides very high sensitivity, low detection limits (3 ng/mL), good precision, and high selectivity at trace levels (Fernandez et al. 1992b). 

FIGURE 9 A direct current plasma emission source. 

Common gas chromatographic detectors that are not element- or metal-specific, atomic absorption and atomic emission detectors that are element-specific, and mass spectrometric detectors have all been used with the hydride systems. Flame atomic absorption and emission spectrometers do not have sufficiently low detection limits to be useful for trace element work. Atomic fluorescence [37] and molecular flame emission [38-40] were used by a few investigators only. The most frequently employed detectors are based on microwave-induced plasma emission, helium glow discharges, and quartz tube atomizers with atomic absorption spectrometers. A review of such systems as applied to the determination of arsenic, associated with an extensive bibliography, is available in the literature [36]. In addition, a continuous hydride generation system was coupled to a direct-current plasma emission spectrometer for the determination of arsenite, arsenate, and total arsenic in water and tuna fish samples [41]. 

Continuous hydride generation with direct current plasma emission spectroscopic detection for total arenic determinations (HY-DCP)... 

K. Panaro and I.S. Krull. Continuous hydride generation with direct current plasma emission spectroscopic detection for total arsenic determinations (HY-DCP). Anal. Letters, 17(A2), 157 (1984). 

I.S. Krull and K.W Panaro. Trace analysis and speciation for methylated organ-otins by HPLC-hydride generation-direct current plasma emission spectroscopy (HPLC-HY-DCP). Appl. Spec., 39,183(1985). 

WL. Childress, D. Erickson, and I.S. Krull. Selenium speciation in dietary mineral supplements and foods by gas/liquid chromatography interfaced with direct current plasma emission spectroscopic detection (GC/HPLC-DCP). Element Spedfic Chromatographic Detection by Atomic Emission Spectroscopy, ACS Symposium Series, Ed. by PC. Uden, American Chemical Society, Washington, DC, 1991, submitted for publication. 

I.S. Krull, K.W Panaro, and D. Erickson. Determination of methylmercury in fish by gas chromatography-direct current plasma emission spectroscopy (GC-DCP). The Analyst, 112, 1097 (1987). 

K.W Panaro and I.S. Krull. An improved analytical approach for organotin determinations via GC-flame photometric and direct current plasma emission detection (GC-FPD/DCP). Appl. Organomet. Chem., 3, 295 (1989). 

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